Electric switch



Dec; 9, 1930.

J. D. HILLIARD 1,784,669

ELECTRIC SWITCH Filed Aug. 26, 1925 I I l I I I l E i -40 I I I I I I II I I I I 2 I I I f- I I I 1 I I|UIJ I I 8 4 I L- 3 I 2/ I I 6 /5 /9 I17 l9 2/ la /7 49 m 19 Inventor.

John D.HLLLLClIfd,

HLs Attorney 0 oil switches.

Patented Dec. 9, 1930 UNITED STATES PATENT OFFICE JOHN D. HILLIARD, OFSOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, ACORPORATION OF NEV YORK ELECTRIC SWITCH Application filed August 26,1925.

My invention relates to electric switches and particularly toswitchesofthe fluid break type having explosion chambers in which arearranged auxiliary or arcing contacts.

One object of my invention is the provision of an improved constructionof switch of this type by which a higher speed of separation of thearcing contacts is obtainable. Another object of my invention is theprovision of an improved connection between the movable arcing contactand the supporting member therefor.

In accordance with my invention I obtain this higher speed of separationby providing alost motion connection between the movable main contactsand the movable arcing con tacts so that in the opening movement of theswitch the movable main contacts are enabled to acquire considerablespeed before the arcing contacts are started on their opening movement.The movable arcing contacts not only thereby have an initially higherspeed but, by reason of the expulsive force of the gases in theexplosion chambers and the aforesaid lost motion connection, rapidlyacquire still greater speed.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

Referring to the drawing, Figure 1 illustrates in a more or lessdiagrammatic manner one embodiment of my invention and Fig. 2illustrates a modification thereof.

In the drawing, Fig. 1, I have shown by way of example the lower ends oftwo insulator bushings 1, such as are commonly employed to support thestationary contacts of Attached to the end of each bushing I have shownthe main stationary contact 2 and the explosion chamber 3. The contactbridge t, when the switch is closed, connects the contacts 2 and formsthe main current carrying path therebetween. Within the explosionchambers are the stationary arcing contacts 5 with which cooperate themovable arcing contact rods 6. Bridging member 7 supports the twocontact rods 6 and has secured thereto at its middle portion the SerialNo. 52,670.

operating rod 8. This rod terminates at its upper end in a head 9 andloosely fitting it is the sleeve 10, to the upper end of which ispivoted the operating lever 11 and to the lowor end of which is securedthe contact bridge 4. It will be noted that the length of the sleeve 10including the contact bridge is somewhat shorter than the length of therod 8 between the bridge 7 and thehead 9. The pur pose of thisdifference is to enable the sleeve 10, the contact bridge 4 and theoperating mechanism therefor to gain speed in the opening movement oftheswitch before the bridge 7 carrying the arcing contacts is engaged.The arcing contact rods 6 are thereby givena relatively high initialvelocity. This high velocity moreover is further increased due to thegas pressure within the explosion chamber formed by the are drawntherein, and because of the lost motion connection between rods 8 andsleeves 10 the contact rods 6 are more easily accelerated than would bethe case were the sleeves 10 and operating mechanism therefor fixed tothe arcing contact rods.

In Fig. 2 I have shown a construction similar to Fig. 1 but with afurther lost motion connection arranged between the arcing contactrods14 and the bridging member 15 which corresponds with member 7 of Fig. 1.The rods 14 are longer than rods 6 and have two limiting flanges 16.Each end of the bridging member 15 carries a pair of opposed plates 17having inturned flanges 18 at the ends thereof and between the platesand the rod 1 1 are rollers 19. Coil springs 20 mounted on guide pins 21provide the necessary pressure between the bridge and the contact rodsfor good conductivity.

Referring to Fig. 2 the initial opening movement of the switch comprisesdownward movement of the sleeve 10 on the rod 8 opening the main currentpath through the bridge 4-, the arcing contact rods 14: remaining infrictional engagement with their co0perating stationary contacts 5. Themoving parts rapidly gain speed and when the bridging member 15 isreached and the lost motion at this point is taken up, this member isgiven an initial relatively high velocity. However,

by reason of the lost motion connection between the arcing contact rods14 and the bridging member 15, further acceleration of the moving partswhich now include the bridging member 15 takes place. At length thelower flanges 16 of the arcing rods are reached and the arcing contactsare quickly separated. The explosive force of the arc gases formed inthe explosion chambers moreover expels the arcing rods from theexplosion chambers with still greater speed, the mass of the rods beingrelatively small, thus again taking up the lost motion provided. A,quick final break in the circuit may thus be obtained even though theswitch and the operating mechanism therefor be of massive constructionfor controlling circuits of large capacity.

lVhat I claim as new and desire to secure by Letters Patent of theUnited States, is:

1. An electric switch comprising a pair of spaced contact members, anexplosion chamber surrounding each member, an operating rod, a. bridgingmember secured thereto, a pair of contact rods, and a lost motionconnection between each of said contact rods and said bridging membercomprising a spring pressed plate carried by the bridging member and aplurality of rollers arranged between the plate and the contact rod.

2. An electric switch comprising stationary main and arcing contacts,explosion chambers enclosing the arcing contacts, movable main contacts,a sleeve connected to said main contacts, movable arcing contacts, abridging member connecting said movable arcing contacts, an operatingmember for both of said movable main and arcing con tacts and a lostmotion connection between the movable main and arcing contactscomprising a rod connected to the bridging member slidable in saidsleeve whereby in the open circuiting movement of the switch thebridging member and the arcing contacts may attain a greater initialvelocity than that of the movable main contacts.

3. An electric switch comprising a pair of explosion chambers eachhaving a socket contact therein, a contact rOd arranged to engage eachof said socket cont-acts, a bridging member supporting and connectingsaid contact rods, an operating rod connected with said bridging member,plates secured to the bridging member on opposite sides of each contactrod, a plurality of rollers bet-ween the rod and each plate, and springspressing together the plates, rollers and contact rods.

4. In, an electric switch, a socket contact member, a cooperatingcontact rod, a transverse supporting member therefor, and meanscomprising a spring pressed roller forming a lost motion connectionbetween the contact rod and the supporting member therefor.

5. In an electric switch, an explosion chamher having a socket contactmember, a movable contact rod adapted to project therein, a support forsaid rod having a lost motion connection therewith and rolling contactmeans between the support and the contact member.

6. In an electric switch, a pair ofexplosion chambers each having asocket contact therein, a pair of cooperating contact rods each adaptedto project into one of the explosion chambers, a bridging member joiningthe contact rods, an operating member secured thereto, a spring pressedpressure plate carried by the bridging member at each end thereof, and aplurality of rollers arranged between each pressure plate and one of thecontact rods.

In witness whereof, I have hereunto set my hand this 12th day of August,1925.

JOHN D. HILLIARD.

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